Which BASH internal variable holds the exit status of the previous command or function?

Which BASH internal variable holds the exit status of the previous command or function?

• $?
• $_
• $@
• $$ 

 

EXPLANATION

$? is a special variable that is internal to the BASH interpreter. It is used to hold the exit code of the previously executed command or function (or even the script itself).

Example:

#!/bin/bash

/bin/true
echo $? #prints 0

/bin/false
echo $? #prints 1

/bin/foobar
res=$?
if [ $res -ne 0 ]
then
  echo "Command foobar failed to execute or exited with a non-zero status: $res"
else
   echo "Command foobar exited successfully"
fi